John Shade, of Climate Lessons blog, sends this report on my debate at St Andrews.

On a wet and windy day, off to St Andrews, where the School of Geography and Geosciences was holding a discussion meeting on climate as one of its World Series Seminars. Speakers: Andrew Montford, and Tom Crowley, a recently retired professor of paleoclimatology. Chaired by Dr Robert Wilson, who said that he was a great believer in discussion where there was discord, and that there was discord in the climate world. He gave Andrew a pleasant and welcoming introduction, noting that he had been quoted in one newspaper report as believing that CO2, all things being equal, will make things warmer.

Before Andrew’s presentation Dr Wilson, tried a quick straw poll of the roughly 60 or 70 people present (my guess, and I also guess that most were undergraduate or graduate students). He asked who believed there had been global warming, and that man had contributed to it – which was a disappointing note since the crucial areas of debate are not on those beliefs, but on the magnitude and other details of climate change over the next 50 to 100 years or so. Then he asked who saw themselves as sceptical. I raised my hand both times, albeit a bit hesitantly the first time. Not many raised their hands the second time – a ‘few’ was how Robert described it.

Andrew’s topic was ‘The Global Warming Debate After Climategate’. He recapped the basic details of Climategate, and of the serious allegations that were raised about climate scientists as a result. He talked through each of the three enquiries and demonstrated that they were all inadequate and had failed to directly address the allegations, thereby earning Andrew’s epithet of ‘whitewashes’. He said people have noticed that these were not serious attempts to get at the truth, and this destroyed trust. He returned again to this theme of lost or damaged trust, noting the IPCC standing by the hockey stick plot even when it knew it was wrong, and of the sleight of graph involved in splicing instrumental readings on to a time series plots of reconstructed temperatures when the reconstructed values turned sharply down instead of up. He noted the curious amount, and direction, of adjustments to temperature records – always to make the present warmer and the past cooler. He did not know whether or not the adjustments were justified, but merely noted that they made him uneasy.

He maintained that trust needs to be rebuilt in climatology, noting that he did not believe all climatologists were corrupt, but that there were some bad eggs in there. He welcomed the willingness of some to discuss issues in a civilised way, and said that both sides need to work very hard to be nice to each other. As more recent development, he noted the facile claim of accelerating warming by doing successive straight-line fits to sections of the temperature record, showing the illustration (due to Paul Matthews) of how this worked in a similar way when done to a simple sine wave. Why did some talk of acceleration based on this?, he asked and noted it as an example of the sort of thing that has to stop. He recalled being told by one climatologist who had posted a 5* review of HSI on Amazon, that he had done so anonymously to avoid repercussions. Turning to recent global temperature reports, he noted that the lack of warming was catching the attention of such as Phil Jones, and of people he had met in the Met Office recently. He noted that climate models had not been working well at the global level, and at the regional level were even worse, and showed a plot contrasting predictions made through the IPCC in the year 2000 diverging up and away from the actuals which were fluctuating about an approximately horizontal trend (chart due to Lucia on the Blackboard blog). He asked if these such models were fit tools for government policy, and said he though not. In winding up, he reiterated that trust has been destroyed, and that the phrase ‘Trust Me, I’m a Scientist’ doesn’t hold water anymore.

Recently retired, Professor Tom Crowley was the other speaker, and his subject was ‘Progress in Understanding Climate of the Last Millenium’. He started by saying he was feeling as bit wrong-footed by Andrew’s talk being different from what he had expected, an observation he was to make again a couple of other times. I think he had been expecting Andrew to be talking mostly about the hockey stick plot.

His introductory slide was of a roadside sign for the ‘Chaos Café’, and this stayed up for quite a while until he got into his main materials. Before then, he invited us to be concerned about the recent high temperatures being reported in the States, with averages in March being 8.6F above normal. He said this was a colossal warming.

He spoke very highly of the IPCC reports, and returned several times to this later. He had used the 1st and 2nd assessment reports as core material for classes he had taught back then on climate. He said virtually nobody has disputed what they have said, and noted that some 50,000 comments on drafts have been responded to. He noted that government representatives had voted sentence by sentence on the Summary Reports.

He showed showed a new plot (not yet published) which had the hockey stick shape using tree rings from 1801 to 1984, constructed using simple averaging of the reconstructions used. He noted that while individual records may be flawed, this averaging helped produce a more reliable result. He talked to some of the major features on the earlier part of the plot, generally referring to volcanic eruptions as likely causes, and then later, from about 1900 onwards by aerosols due to industrial pollution. He showed a plot of sulphate depositions found in Greenland ice – in the flight path of the prevailing winds from the US. These showed a drop in the 1930s which he associated with the Depression of those years, a drop which was not recovered from on the plot until 1954, roughly following a similar performance in the Dow Jones Index. The Clean Air Act in the 1970s led to improvements, but before that there was a surge of readings from abour 30ppb to 200ppb at their peak. This he described as great wads of sulphur, having earlier asked any gardeners present if they would deliberately pack sulphuric acid powder around the base of their valued plants.

He showed another plot with global temperatures (mostly as per Hadcrut means as I recall) , with CO2 growth almost perfectly superimposed from about 1800 to the present, and once again invited our concern. A further, yet to published plot due to Levitus, showed substantial heating in the upper ocean. All this he described as rock solid.

He said the IPCC view was that doubling of CO2 would lead to global mean temperatures rises of 2 to 3C in 30 years from now, and these would be the highest in a very long time (I cannot decipher my notes on the actual time period). He repeated the assurance of the IPCC about continued warming, and his confidence in the IPCC.

My notes are a bit scrappy for the question and answer session which followed, and which was ably handled by Dr Wilson, since I was from time to time formulating questions or comments of my own.

An early question concerned differences in variability displayed on different sections of plots shown by Tom – described by the questioner as ‘huge differences in uncertainty’. Another questioner argued that a detailed re-analysis of tree-ring data was called for in general. The question of how much longer a period without warming would cause people to say something was wrong with the models and/or the claims of a warming threat. Tom suggested that if warming not resumed by 2020, that would cause concern. A questioner noted that there were massive leaps being made from projected temperature rises to talk about climate impact in general – impacts that have not been remotely justified e.g. talk of floods and droughts and famines and so on.

The excess winter deaths in Scotland were raised to illustrate more harm from cooling than warming here. An audience member claimed that climate scientists were intrinsically sceptical – that was part of science, and that it was very misleading to think of a simple divide between climate sceptics and true believers. The same person also praised peer review as one of the strengths of climate science, and urged sceptics to get engaged and try to get published. There was some mention of Arctic ice thinning, the high variability Arctic sea ice and thickness so that even a dramatic summer melt at the pole would not be unprecedented even in the last 100 years, of sub-tropical drought forecasts and poor guidance to the Australian government about permanent drought down there (with desalination plants build not long before floods due to very heavy rains appeared and the plants were mothballed).

The Clausius-Clapeyron relationship was raised to note airborne water vapour would increase with rising surface temperatures, and that led to questions about negative feedbacks involving clouds tending to counter such rises). Someone noted that economic models also needed a lot more examination. What should be done? Bets were bandied about about temperature rises in the near future. It was noted that the self-interest of developing states such as India and China may not coincide with greenhouse gas reduction. Tom said it would be in the self-interest of the States to reduce dependence on imported oil, and that in general people should try to do what benefits their own country. A questioner had asked if it seemed that global governance was the only way to go if greenhouse gas reductions were to be addressed.

The climategate scandal was mentioned, and Tom said that it had nto affected the science, and that anyway, scientists were human beings. He felt that if there was 1 dodgy paper out of 100, that one would be blown up out of all proportion by the blogosphere. A suggestion of massive oil funding by an audience member was greeted with derision by the ‘sceptics’ present, and when Tom started to talk of Exxon in particular, there was a remark from the audience to the effect that going down that line would make ‘us’ no better than the sceptics, and that produced an approving murmur in the audience and the topic was dropped. A questioner asked what would it take to change a sceptic’s mind – for example, if they saw there was only a 1 in 20 chance that the projections were right about CO2, what would they do? The case of the resigning editor and reviewers at the Remote Sensing journal was raised, by Andrew I think, as an example of something wrong with the science – if a weak paper gets through, why not simply print a rebuttal, why resign, and why, in particular, apologise to Trenberth – a man not in the speciality in question. Andrew raised the question as to whether peer review was adequate in climate science, and the politicised situation. I think there was consensus that peer review is not perfect and that moves to open peer review were a good development. Several people pointed out that both sides of the debate had been politicised.

The discussion had been, as they say, wide-ranging and often lively. But always temperate, and my impression was that everyone would have felt they had some opportunity to be heard. Dr Wilson helped keep an even keel, and invited us all to another room nearby for refreshments and further discussion. All in all, a worthwhile event with some good communication of perspectives and bits and pieces of ‘facts’. Would that such events, in such an open and courteous atmosphere, could be held far and wide. They weren’t in the past, and we were told by some that the debate was over. I think for most of us, it has in fact scarcely begun. Back to the car park to find some of the West Sands had been spread there by the wind to give a slightly Saharan look to the place."

Reader Comments (365)

Chris acknowledges that the scientific peer-reviewed system can let dodgy papers through. Dr Wilson uses a few dodgy comments on a blog as a reason to retract his apology. This is a comedy cross-talk duo which needs to polish up its act.Omnologos/Maurizio is the clear winner for his successful prediction that this would be a waste of time. The Bishop is the loser, since his patience, politeness and occasional censorship of his own supporters has been rewarded with a slap in the face. (Professor Betts has also been made to look silly by his colleagues).Presumably a look at the geographic source of hits to this thread could confirm or disprove Green Sand’s theory (Apr 28, 2012 at 9:26 PM) that this was all meant for the amusement of Dr Wilson’s students?

It appears that the Greener Shade of Blue meeting arranged by the Policy Exchange and mentioned above by Fay Tuncay is likely to be most concerned with finding out how to convert sceptic minds, not in listening to their arguments. Just look at the rest of the panel, in addition to Peter Lilley:-

HuhneToTheSlammer - no problem. You may also find this a useful resource for weather/climate history. I have no idea who maintains it, but there's a lot of information on there (collated from a number of sources, including Lamb). Mostly weather events of course, but these alone show that contemporary windstorms, floods and droughts (which are now regularly attributed to CO2 by people who should know much better), are nothing unusual.

Why would the environment editor of the Grauniad profess to be a Conservative? It just does not compute. Unless he's there to provide "balance"? Here's hoping that some of the attendees turn the greener members of the Greener Shade of Blue panel A Whiter Shade of Pale with their imperviousness to climate change propaganda.

btw - Figs being exported from Buckie is a new for me, tell me more. Afaiak the most northerly fruiting tree today is in Perthshire. But just like pears, to get them to fruit and ripen here they have to be grown in a sheltered and south-facing location. There is also a 'wild' peach tree in this locality which produced fruit (not many but they were big, and quite edible) in 2006, 2007, 2008. Not the last two years though, the resumption of cold winters and summers have put a stop to that. It is in a very sheltered spot, on waste ground beside a small waterfall, I think the water ameliorates the worst of the extreme winter temperatures, and the UHI from neighbouring buildings helps too.

MessengerDr Adam Corner, one of the speakers at the Greener Shade of Blue meeting, is a believer who is willing to engage in dialogue with sceptics. He kindly provided me with information about research he has conducted into us sceptics, despite me having been quite rude about it in comments athttp://www.climate-resistance.org/2012/03/shrinking-the-sceptics.htmlHe can be reached via his blog athttp://talkingclimate.org/

Should you chance to look at this thread again, I want to say that I first (like many) appreciated that you took the trouble to moderate the forum at St. Andrews which was reportedly conducted with excellent civility and intellectual scruples. Then you took the time to post a comment here, apparently encouraging more discussion. So far so good, and a credit to you....

Except that you included the curious, inflammatory statement that there was really nothing to debate or discuss except around the margins..... so you risk undermining your entire project in more open "science communications" by indicating that it is really just an empty charade.

Then you feel pity and dismay that some of the first 19 (only 19, not all of which referred to your comments) posters in a period of only a few hours did not race off to read your scientific papers and realize that you .... what.... are not as dogmatic as you appeared to be in your initial comment??

I'm still unclear as to what exactly the "trap" is supposed to be..... that people are not supposed to comment upon your comment until they race to read all of your scientific papers?? That people are not supposed to be irritated when you indicate your disdain? It was not exactly a "civil" way to proceed here.

It strikes me that you set and fell into quite a "trap" for yourself.... to the extent that you were seeking to model for us a combination of rigor, scientific spirit, and open-mindedness here, I'm not seeing it. Seems to me that you undermined your own purposes and left at least a large proportion of people here with a negative impression of your commitment to better "science communication" with the public.

However, I do appreciate that you are willing to engage at all, which is more than many of your peers attempt to do. I'd simply suggest that you re-consider this approach. I don't see what it accomplished for anyone, really.

"I purposely posted a goading statement to test the waters. I got what I expected which was a pity."

I haven't seen the video yet, and look forward to it, but a quick skim of the numbers and a quick reading suggests that the response you garnered shouldn't really tell you anything unless you extrapolate well beyond the data to hand.

At 17:22 you posted your comment, ostensibly to test the waters by "goading".

At 21:14 you decided that the experiment was over and declared yourself somehow satisfied that the response was what you expected, and you were disappointed but not surprised. I assume - but stand to be corrected - that this is a reference to the workings of the skeptic mind?

So what happened in between?

There were 19 posts over the course of < 4 hours.

Of those 19, at least 7 were very general comments or questions, the odd poem, and a degree of praise for engagement.

This leaves 12 comments over 4 hours where the content of the post *may* have had some critical element, or fallen into the trap you describe post-hoc. And I believe I've only excluded those that very obviously didn't fit the profile you claim to have detected.

Do you think that the number of responses you garnered over this period its sufficient to allow you to draw a conclusion?

Note, not the number of responses since then - I have no doubt you've managed to push quite few additional buttons in the meantime - but the responses you had to hand when you made your second comment?

Chris: I was beginning to enjoy this debate and have been following it for a few days. But then, I realised that you were beginning to be the fount of all knowledge; that there wasn't a thing you were not an expert on; that you must be a great and well-published scientist. And then you said this:

So I Googled it. They are not your words. Why is it, Chris, that you do not give proper references for the quotes you use? Why are you giving the impression that you are using your own words? It is obvious to me that you are not. It is also obvious that you are not stupid - yet you think 'we' are - and yet you do not give proper approbation to your arguments. I've twigged you now. It's called plagiarism. Your subsequent arguments fall by default.

mrsean2k: Juvenile is the adjective that springs to mind. You should note that Dr. Williams reappeared to tell Chris, the chap who believes models can foretell the future, that he's wasting his time on this thread. Given his peculiar beliefs in foretelling the future using models I'd say he would be wasting his time pretty much wherever he was, although he did seem an awfully nice guy, and I wouldn't mind further contact with him(or is it a her?) to pursue with him/her how the models can foretell future weather events.

It has to be admitted that Dr Watson has stimulated some conversation, and I'm sure he's a nice chap, but he should know that he does come across as believing he's yummy. In fact as the old saying goes he looks as though "if he was made of chocolate he'd eat himself."

"That's pretty much like the difference between weather simulations and climate simulations. In a world with enhanced greenhouse warming, and within a defined greenhouse gas emission scenario, we're likely to have a reasonable chance of predicting a plausible range of global temperature for the decade 2070-2080 (climate); however I wouldn't be making a bet on whether we should be taking our umbrellas to work in St. Andrews on October 17th, 2073 (that's weather)."

I think you've missed my point, by a country mile, but accept that I've been dashing off responses and it is probably my fault that you did. First of all you said that the models were making predictions, so let's deal with that.

"In fact there are no predictions by IPCC at all. And there never have been. The IPCC instead proffers 'what if' projections of future climate that correspond to certain emissions scenarios...”

KevinTrenberth, Nature Blog, June 2007

As you and your friend Dr Wilson have come to understand we're a pretty thick bunch here so we don't make things up we go and find out what's being said, because we're not clued up enough to bluff.

So who am I to believe, you or Kevin Trenberth?

You went on to praise the models telling us how accurate they are and how they have a track record of being right, from memory you quoted a rubbishy professor called Lindzen who said the water vapour in the troposhere wouldn't go up in a warming world. I doubt he said that as he's a leading atmospheric physicist, and you're not, but both you and I would agree that warming causes more water in the atmosphere through oceanic evaporation.

As to the models again I'll return to Dr. Trenberth:"They are intended to cover a range of possible self consistent “story lines” that then provide decision makers with information about which paths might be more desirable. But they do not consider many things like the recovery of the ozone layer, for instance, or observed trends in forcing agents. There is no estimate, even probabilistically, as to the likelihood of any emissions scenario and no best guess."

Following on he said:

"Even if there were, the projections are based on model results that provide differences of the future climate relative to that today. None of the models used by IPCC are initialized to the observed state and none of the climate states in the models correspond even remotely to the current observed climate. In particular, the state of the oceans, sea ice, and soil moisture has no relationship to the observed state at any recent time in any of the IPCC models. There is neither an El Niño sequence nor any Pacific Decadal Oscillation that replicates the recent past; yet these are critical modes of variability that affect Pacific rim countries and beyond. The Atlantic Multidecadal Oscillation, that may depend on the thermohaline circulation and thus ocean currents in the Atlantic, is not set up to match today’s state, but it is a critical component of the Atlantic hurricanes and it undoubtedly affects forecasts for the next decade from Brazil to Europe. Moreover, the starting climate state in several of the models may depart significantly from the real climate owing to model errors. I postulate that regional climate change is impossible to deal with properly unless the models are initialized."

Now I believe that Dr. Trenberth was giving a fairly accurate report on the state of the models, and nothing has happened to change that belief, but if you disagree with Dr. Tenberth let us know where an why he's wrong.

Now the difference between climate and weather, I thought I had a pretty good grasp of it. You know if you live in a good climate, the weather is good. If you live in a bad climate, the weather is bad. "Good" and "bad" being generalistions of the average sort of weather you could expect.

Telling the policy makers that the climate will be warmer isn't very informative, a warm climate could be spectacularly brillliant, like Thailand's of spectacularly awful like the Gobi Desert. There's no information in "warm" (you could always try taking a course on information theory, it might help when communicating with the great unwashed). I assume you've gobbled up the IPPC AR4, most of which is very good science by the way, but the SPM deals with weather, not climate. It tells us we're going to have more droughts (in a world with excessive moisture in the atmosphere no less!), more tropical storms (in a world with a lower temperature gradient between the poles and the equator than today), and all manner of nasty weather events.

Which brings me to the models again, currently the Met Office produces 5 day forecasts based on "temperature, rainfall, wind speed and direction, air pressure etc.", your words, they run them through the same computers that are you're telling us can forecast the temperature in Helsinki in August 2090 (I can tell you it will be warm), these same computers can actually see the weatherfronts crossing the Atlantic, and have satellite data transmitted to them giving wll the known information on the parameters above, but the five day forecasts are, well, at best, hit and miss.

geronimoAren't "story lines" things you have in soap operas like 'East Enders' or 'Neighbours'?Pre-requisite being that they are as far removed from reality as possible? Perhaps Trenberth has a point here!

Why is it the average of the 2 surface and 2 satellite measurements over 30+ years is +0.3C -- less than that directly attributable to CO2 by itself, without any accompanying positive feedbacks? As opposed to, say, predictions of +0.3C per decade?

First, the increase over 30 years looks closer to 0.4C than 0.3C (eyeballing linear trendlines on Wood for Trees). But mainly, the larger predictions are based on equilibrium sensitivity, so the timescale depends on the rate at which lags and feedbacks work through the system. There is some uncertainty there. Note, however, that the rate of increase in GHGs is currently considerably faster than it has been in earlier (non-anthropogenic) excursions.

lapogus, can you explain more about what is in that graph? You seem to have constrained the temperature record between two linear trendlines, but you give no indication of what those trendlines represent. Also, by presenting a variable that varies between 13 and 14 on a y-axis that goes from 8 to 17, you've flattened the trend, making it more difficult to appreciate. And what is the horizontal line at y=9?

That's pretty creepy snotrocket. It would be a shame if the owner of this blog considers your sort of stuff acceptable.

Out of curiosity I also googled my words "strong contribution from somatic mutations in susceptible tissue" and I get:

No results found for "strong contribution from somatic mutations in susceptible tissue"

That's probably because that phrase came to my mind last night when I was thinking of a good analogy to describe an aspect of scientific understanding for Andy; Google hasn't yet picked it up in it's interned trawls.

Of course if you Google without the quotes you find many examples of the use of the words "somatic" and susceptible" and even "susceptible tissue" and "somatic mutation". That's because these words are pretty common when considering the cell biology of cancer, for example.

Even 'though I've tried to ignore them, many of the responses here are awesomely disgraceful - I do hope there are some posters here that find your sort of creepy behaviour a little embarrassing for what is supposed to be a science blog...

chris:Conceptually, you are wrong. Firstly, given the intuitively obvious etiologic contribution from cigarette smoke to lung cancer, that everyone including non-specialists can grasp, the ratio of relative contribution of environmental tobacco smoke to lung cancer incidence is of the order of 0.01. The source is US cancer statistics, ~3000 new cases of lung cancer occur every year that are putatively attributable to ETS, compared to a total annual incidence of 200,000+ new lung cancer cases.

Which means, contrary to your intuition arising from cancer biology, the epidemiologic signal of cancer risk from environmental tobacco smoke is actually pretty weak. It is a miracle of modern-day public health data collection (and moralizing about smoking) that we are actually able to reliably detect this signal. In other words, any 'depth' of understanding of processes is still no guarantee as to the reliability of our predictions.

In the same vein, there are many 'expected' phenomena that have not occurred in climate studies, and many unnexpected ones that have occurred - for which climate science, as represented by you, offers post-hoc explanations shamelessly and carries on as though it never said what it said. Each one of these instances is actually a deadly hit against the original hypothesis, but becomes immaterial, as the climate beast mutates rapidly enough!

Rob Wilson falls into the same trap as do many other British academics ... that of believing they know everything about everything, whilst actually being insufficiently intelligent to recognise the arrogance in themselves and their pronouncements that can mightily piss off their fellow man.

Or piss me off, at least - probably because I've had the misfortune to have had to deal with far too many Rob Wilsons during a long career in British company management.

The controversy around lung cancer and smoking lies primarily around ETS. The 'doubt merchanters' conflate this to the story of primary risk from active smoking itself.

With this in mind, chris' original example about mutations and susceptibility is doubly wrong for the purpose he used it. Cigarette smoke is an experimentally verifiable carcinogen in animal models and cell cultures. It is an epidemiologic risk for cancer in humans in populations. The model is dissimilar to tested reality only in details and the targets.

Imagine a computer model of a mouse - which replicates all aspects of a real mouse - ranging from its respiratory and cardiovascular functions down to its cell biology - being made to inhale virtual tobacco smoke. Imagine the virtual bronchial lining cells of such a model mouse developing into cancer cells. That is the correct analogous situation we are in with respect to climate modeling.

Oh dear! Why not read my original post Shub, (Apr 28, 2012 at 6:11 PM | chris) and find out what I was actually talking about. I wasn't inferring anything about ETS. If you can't be bothered to read my post, let point out that in responding to Andy's question of how we might know if any model we might care to consider, is right but for the wrong reason, I was using our understanding of ciggie-smoking - morbidity/mortality relationships to illustrate that our knowledge has "depth", and this is often how we know we are right for the right reason.

e.g We can predict that more smoking raises the likelihood of respiratory disease and lung cancer in individuals and populations not just because we have epidemiological evidence, but also because we understand the causalities involved. Thus as well as epidemiological evidence, we can also assay for somatic mutations (e.g. in tumor suppressor protein coding sequence) in cellular DNA of susceptible tissues (e.g. from lung biopsies). That sort of thing, yes?

Nial: Hi. I'm familiar with Google search formats. And I can quite easily find this from Alfred Knudson:

"According to a two-hit model, dominantly inherited predisposition to cancer entails a germline mutation, while tumorigenesis requires a second, somatic, mutation. Non-hereditary cancer of the same type requires the same two hits, but both are somatic."

Sound familiar?

Like I say, take a look at http://www.springerlink.com/content/h3p676g386674615/

I figure if I did some more digging on Chris's 'comments' I would find they actually belonged to someone else. Now, I don't mind anybody quoting someone's work, but the idea is that you give credit where it's worth. And for what it's worth, I cam up with the words to this comment as I was tucking into a lovely piece of roast pork. Of course, it could be that it 'came to me last night' (Props: Chris.)

chrisI read what you wrote. Salopian was right - there is no safe level of smoke, and conversely there is nothing called 'enhanced smoke'.

More importantly, our model of experimental understanding of the cancer biology of carcinogens present in tobacco smoke is underpinned by both model and test subjects being physical entities that exist fully formed in reality. As opposed to climate where we have create our model by putting together virtually what we understand, in order to test parts of the same understanding. So our position becomes circular and due to this element of circularity, we cannot fully resolve possibilities of models being right for the wrong reasons.

snot,Knudson's two hit hypothesis is widely understood. Carcinogens do 'cause' somatic mutations - although our understanding is much more nuanced than that. Even this is widely known. I would think chris has license to use these, without citation.

"That's pretty much like the difference between weather simulations and climate simulations. In a world with enhanced greenhouse warming, and within a defined greenhouse gas emission scenario, we're likely to have a reasonable chance of predicting a plausible range of global temperature for the decade 2070-2080 (climate); however I wouldn't be making a bet on whether we should be taking our umbrellas to work in St. Andrews on October 17th, 2073 (that's weather)."

I think you've missed my point, by a country mile, but accept that I've been dashing off responses and it is probably my fault that you did. First of all you said that the models were making predictions, so let's deal with that.

"In fact there are no predictions by IPCC at all. And there never have been. The IPCC instead proffers 'what if' projections of future climate that correspond to certain emissions scenarios...”

KevinTrenberth, Nature Blog, June 2007

As you and your friend Dr Wilson have come to understand we're a pretty thick bunch here so we don't make things up we go and find out what's being said, because we're not clued up enough to bluff.

So who am I to believe, you or Kevin Trenberth?

You went on to praise the models telling us how accurate they are and how they have a track record of being right, from memory you quoted a rubbishy professor called Lindzen who said the water vapour in the troposhere wouldn't go up in a warming world. I doubt he said that as he's a leading atmospheric physicist, and you're not, but both you and I would agree that warming causes more water in the atmosphere through oceanic evaporation.

As to the models again I'll return to Dr. Trenberth:"They are intended to cover a range of possible self consistent “story lines” that then provide decision makers with information about which paths might be more desirable. But they do not consider many things like the recovery of the ozone layer, for instance, or observed trends in forcing agents. There is no estimate, even probabilistically, as to the likelihood of any emissions scenario and no best guess."

Following on he said:

"Even if there were, the projections are based on model results that provide differences of the future climate relative to that today. None of the models used by IPCC are initialized to the observed state and none of the climate states in the models correspond even remotely to the current observed climate. In particular, the state of the oceans, sea ice, and soil moisture has no relationship to the observed state at any recent time in any of the IPCC models. There is neither an El Niño sequence nor any Pacific Decadal Oscillation that replicates the recent past; yet these are critical modes of variability that affect Pacific rim countries and beyond. The Atlantic Multidecadal Oscillation, that may depend on the thermohaline circulation and thus ocean currents in the Atlantic, is not set up to match today’s state, but it is a critical component of the Atlantic hurricanes and it undoubtedly affects forecasts for the next decade from Brazil to Europe. Moreover, the starting climate state in several of the models may depart significantly from the real climate owing to model errors. I postulate that regional climate change is impossible to deal with properly unless the models are initialized."

Now I believe that Dr. Trenberth was giving a fairly accurate report on the state of the models, and nothing has happened to change that belief, but if you disagree with Dr. Tenberth let us know where an why he's wrong.

Now the difference between climate and weather, I thought I had a pretty good grasp of it. You know if you live in a good climate, the weather is good. If you live in a bad climate, the weather is bad. "Good" and "bad" being generalistions of the average sort of weather you could expect.

Telling the policy makers that the climate will be warmer isn't very informative, a warm climate could be spectacularly brillliant, like Thailand's of spectacularly awful like the Gobi Desert. There's no information in "warm" (you could always try taking a course on information theory, it might help when communicating with the great unwashed). I assume you've gobbled up the IPPC AR4, most of which is very good science by the way, but the SPM deals with weather, not climate. It tells us we're going to have more droughts (in a world with excessive moisture in the atmosphere no less!), more tropical storms (in a world with a lower temperature gradient between the poles and the equator than today), and all manner of nasty weather events.

Which brings me to the models again, currently the Met Office produces 5 day forecasts based on "temperature, rainfall, wind speed and direction, air pressure etc.", your words, they run them through the same computers that are you're telling us can forecast the temperature in Helsinki in August 2090 (I can tell you it will be warm), these same computers can actually see the weatherfronts crossing the Atlantic, and have satellite data transmitted to them giving wll the known information on the parameters above, but the five day forecasts are, well, at best, hit and miss.

Shub: I found many passages that contained some, or nearly all the words used by Chris. He has been clever enough not to use Knudsen (etc) word for word, but the links I have put up earlier certainly get you into the ballpark. The thing is, the matches are just too close for comfort. That, and all the other gems of info that he comes up with (such that he is the very definition of a polymath) just raises my BS detector somewhat. So much so, I started to wonder how his comments would fare under an Gleick-like analysis by Stylometry (JGAAP: Ref: http://wattsupwiththat.com/2012/02/22/an-online-and-open-excercise-in-stylometrytextometry-crowdsourcing-the-gleick-climate-strategy-memo-authorship/)

Not sure I want to carry on with this too much if you don't mind geronimo, since this is extremely time-consuming. But you've written a long post and I'll address a couple of things.

Predictions/projections. You're absolutely right. We can't make predictions partly because we don't know things like emission scenarios. So we use our knowledge/models to make projections according to certain scenarios. That's why I used the phrase "In a world with enhanced greenhouse warming, and within a defined greenhouse gas emission scenario, we're likely to have a reasonable chance of predicting a plausible range of global temperature for the decade 2070-2080". Definitely believe what scientists say in their considered thought over what people type on blogs, since the latter, as you say are often “dashing off responses” and don’t always convey exactly what they mean!

Lindzen on tropospheric water vapour.

"...from memory you quoted a rubbishy professor called Lindzen who said the water vapour in the troposhere wouldn't go up in a warming world. I doubt he said that as he's a leading atmospheric physicist and you're not..."

Well you’re right that I’m not a “leading atmospheric physicist”! However Dr. Lindzen has a habit of saying stuff that is unlikely to be or isn’t true. One could suggest that he likes being provocative at least in his earlier days.

Lindzen argues in his 1990 paper in Bull. Met. Soc. Am 71, 288-9 (1990) that enhanced cumulus convection in a warming world is likely to cause drying in the upper troposphere. There’s a very interesting discussion with James Hansen in Nature vol 349, 467, 1991), in which Lindzen reasserts this idea and Hansen points out that physics (i.e. models) strongly indicate a moistening of the upper troposphere in a warming world and even points out that some of the very early satellite data tends to support that. We now know pretty categorically that Lindzen was wrong and that Hansen (and the models) were right.

”Thick bunch”: All I can say is that I have no such thoughts, but there are various levels of defensiveness on this blog. Incidentally I had never heard of Dr. Wilson before yesterday.

Model predictions Some things are predicted quite well, other things less so. I hope that I was quite specific in my description of things models have been shown to predict well (e.g. enhanced tropospheric water vapour concentrations; delayed Antarcic warming; raised tropopause and cooling stratosphere; intensified water cycle and latitudinal precipitation patterns – empirical measures of those sorts of things are directly comparable with predictions from 20-30 years ago). We’re less confident in other potentially predictive aspects of models. I’m pretty sceptical about the ability of climate models to predict fine scale regional effects. Of course I’m no expert and so my degree of skepticism may or not be well-founded.

Weather/climate Not sure we disagree. We are predicted to have more droughts in a warming world even with enhanced tropospheric water vapour. We’re also expected to have stronger precipitation events as the water cycle intensifies. However this has a strong latitudinal dependence (low latitudes = more drought; higher latitudes= more rainfall) according to predictions/models (I cited a few papers in an earlier post somewhere in this long thread)!

Is this a change in weather or in climate? There’s a certain element of semantics in that. One might say that as regions of mid-latitudes progress to greater drought conditions they will be entering into a shifted climate-state. Not sure at what point a change in average weather becomes a new climate state, but no doubt there’s a definition of this somewhere.

Forecasting summer temperatures in Helsinki in 2090 Within a given emission scenario, I expect climate simulations might do a reasonable job of projecting average summer temperatures in Helsinki at the end of the 21st century (climate). They’re likely to be very poor in determining whether it will be overcast with light showers on September 28th 2091 (weather). That’s how I see it to the extent that it can easily be conveyed in a messageboard. I’m happy to agree to differ if you have another POV!

I really hope you feel you can stick around here, as I think you have a lot to contribute. Especially since, unlike me, you actually know about palaeoclimate reconstructions, and don't work for the Met Office either so don't bring all that baggage with you :-)

But I can see you have unfortunately got off on the wrong foot with some people here. To be honest that was inevitable - there are a wide diversity of views represented in the Bishop Hill readership, and whatever you say, someone won't like it. I don't think I have ever said anything here that does not seem to have upset somebody somewhere! I reckon that even if Dick Lindzen came here, someone wouldn't like what he said!

But what worries me is that more people now seem to be getting upset not with your original remark about AGW, but about the conversation afterwards, and in particular, the perception that they are all being lumped in together. In reality there is a wide range of viewpoints here, so it is important not to let a noisy few give the impression of speaking for the majority.

My feeling is that a lot of people here do basically agree that AGW is real, but are less convinced that it is catastrophic or even something that needs to be avoided. And to be fair, it's that issue ("How bad will it be?") which is a key one for science now, and a focus of most research in the area.

So my plea to you Rob (and indeed everyone on Bishop Hill!) is, let's not throw the baby out with the bathwater. There will be people between whom there are irreconcilable differences, but also there are many more who just want a sensible discussion. You've stated that your position (like mine) is that AGW is fundamentally sound - others disagree on that particular point, but not everyone. Let's just agree to disagree on that particular point, and move on to the more interesting and important question of the extent and severity of future warming and its impacts. Although most recent research tends to point to future impacts probably being negative overall and something we'd wish to avoid, or have to take major steps to live with, there are wide uncertainties in all this and important decisions are being taken in the face of this uncertainty. It's definitely worth discussing the issues here.

Palaoeclimate reconstructions are important to this second question as they indicate whether the warming is unusual or not, and hence whether the world has lived through these things before. It's fantastic to have someone who knows about these things being willing to contribute here :-)

Not sure of the relevance of the fact that there is no level of safe smoking to my point about the fact that the epidemiological predictions of the consequences of smoking are underpinned about knowledge of mechanistic causality!

Still, that sort of misunderstanding is an inherent problems in using analogies to illustrate concepts...

More to the point, our understanding of climate models does have the sort of testable "depth" that relates to morbidity predictions in ciggie smoking, although it's obviously not so strong. One can look at predictions from models made 20 or 30 years ago, that not only predict global warming under enhanced greenhouse forcing, but also predicted that since the warming results from enhanced radiative forcing at the top of the atmosphere, the stratosphere would cool a little as warming progressed; our understanding of the effects of land distribution and ocean circulation in polar regions predicted that the Arctic would feel the brunt of early greenhouse-forced warming with a delayed response in the Antarctic; the models predicted intensified water cycle behaviour and specific precipitation trends that can be empirically assessed; they predicted enhanced tropospheric water vapour concentrations... and so on.. we have enough empirical observations to know that so far these predictions have accrued in the real world...so our models are likely to be correct for the right reasons to the extent that these observations are so far indicative.

Other than that, I'm not going to disagree with you that the future is rather uncertain and our ability to predict/project this with models also has considerable elements of uncertainty...

...I'm probably not going to respond much more (sigh's of relief all round!) since I do need to get back to my day job.

P.S. many thanks for granting me licence to use the words "somatic mutation" without penalty!

"My feeling is that a lot of people here do basically agree that AGW is real, but are less convinced that it is catastrophic or even something that needs to be avoided. And to be fair, it's that issue ("How bad will it be?") which is a key one for science now, and a focus of most research in the area."

Hopefully the new research is prioritised against other world problems that could benefit from real brainpower properly applied.

My feeling is that a lot of people here do basically agree that AGW is real, but are less convinced that it is catastrophic or even something that needs to be avoided. And to be fair, it's that issue ("How bad will it be?") which is a key one for science now, and a focus of most research in the area.

Well I may be speaking only for myself, but I will add another category: people who think that even if it were "catastrophic" or "something that needs to be avoided", that would be irrelevant. There is no way that CO2 emissions are going to be reduced in the next few decades or so, simply because there is no energy source that's going to be implemented world-wide to replace that generated by carbon-based sources to any significant extent. Nuclear could do it, but it's clear that, politically, it simply won't be implemented; that's why people prefer the feel-goodery of wind turbines instead.

There's no power on Earth that's going to make China, India and the US - let alone lots of other developing countries - really reduce their CO2 emissions; but some countries may be foolish enough to commit economic suicide on their own - or at least make some gestures in that direction, such as the UK's Climate Change Act and Australia's carbon tax, which is bad enough.

I take it as given that whatever happens - or not - to the climate due to increased CO2 concentrations in the atmosphere, will happen (or not). If something does happen, then, we'll see that will be done or can be done or needs to be done. But for some very silly nations (or groups of nations like the EU) to think that they can do something about controlling the global CO2 emissions, is the ultimate in self-delusion.

chrisYes, there have been many predictions that have been made, but:i) several of them were ex post facto, i.e., theory followed after observations changed course. If you examine Harold Ambler's book, and any of Steven Goddard's posts on historical weather trend and climatic predictions, you'll find evidence for thisii) some of these predictions would be true in a warming system, irrespective of causeiii) some of these predictions have not come to pass

Consequently it does not add up to a coherent whole. The question therefore is, should we be ruthless in our exclusion and acceptance of evidence - as sceptics would like, or do we say, "come on,. what else can it be?" as climate scientists like to say?

Secondly, there is a problem with respect to using to analogies, no doubt, and you are not to be blamed for that. We all have to give some examples! But, the more fundamental difference of non-equivalence between systems where experimentation or quasi-experimentation is possible in one, and no experimentation is possible in the other, should not be lost on us.

Hi Richard,I agree on a certain point:

I do think Rob's course through this thread, partly, has been a victim of blog interaction mechanics. He states correctly that this forum is not perfectly suited for one-on-one replies. But it is difficult to understand why he would kick the hornet's nest, piss off dozens of people and then complain that he cannot respond to each one of them.

Chris, thanks for your response, but I didn't write a long post, Dr, Trenberth did and I copied and pasted. I'm sorry you hadn't heard of Dr. Wilson before this post, neither had I. Having heard from him I'm left with the impression of a rather juvenile individual who talks about "tests" being failed ( or is it passed?) and "kicking hornet's nests" which I find a bit juvenile.

Richard Betts, it's always nice to exchange ideas with people, but when doing so those with the knowledge would do well to do so with humility, for a whole raft of reasons. Dr. Wilson's appearance here seems to have been some sort of self-indulgent attempt to anger and humiliate the people on these threads, who he clealy holds in contempt. Prof Jones has described you as "implausibly nice" an epithet I've long yearned for for myself, with no success, so your attempt to draw said Dr. Wilson back into discussions, while admirable and "nice", I fear is doomed to failure.

I watched Judith Curry make the same journey on ClimateAudit, from convinced scientific belief in AGW to, "Maybe they have a point." My guess is that you want us to move in the other direction to say, "Maybe they have a point about CAGW." Dr. Wilson has no such illusions, he'll not engage here other than to sneer at the contributors because they're mostly non-scientists and therefore cannot possible understand the issues.

1 If CO 2 is going to cause catastrophic global warming we are helpless to stop it.2. If were are to mitigate the effects none of the policies put forward by the greens will help.3. We should wait and see.

"Let's just agree to disagree on that particular point, and move on to the more interesting and important question of the extent and severity of future warming and its impacts. Although most recent research tends to point to future impacts probably being negative overall and something we'd wish to avoid, or have to take major steps to live with, there are wide uncertainties in all this and important decisions are being taken in the face of this uncertainty. It's definitely worth discussing the issues here." Richard Betts

Dr Betts,

Writing as a simple layman it is evident to me that the records of past temperature - air, sea, you name it - are extremely patchy, and impossible to verify save in the very recent past (which is simply too short a timescale to assess meaningfully any medium to long-term changes in climate). Furthermore the raw data are subject to a great deal of adjustment - some of it very odd, and unexplained - by those who store them and use them for research. On this basis alone I cannot accept GW as proven, let alone AGW.

However, for this discussion I will accept that AGW exists. But you write of "warming and its impacts" alone. What about other possible changes in climate ? Do you want us on BH also to accept changes in precipitation, in cloud cover, in extremes between day and night temperatures, in the number and severity of "extreme events", for example ?

Before considering "impacts of warming" surely we must discuss what other aspects of weather and climate may be - or are being - influenced by man, and the evidence for that ? Or do you consider that AGW itself will produce these other changes in climate ?

Richard Betts: "My feeling is that a lot of people here do basically agree that AGW is real, but are less convinced that it is catastrophic or even something that needs to be avoided."

Allow me to say, how wonderfully emollient of you. And how arrogant to presume that you know how so many of us feel. I shall not speak for others: I know where I stand on AGW. It is not so 'A', as you would have me believe; it is not so 'C'(atastrophic) either; and, as far as I'm concerned, we need to be far more concerned with the effects of disastrous cooling than we need to be by what may well turn out to be about 1/3rd of a degree of warming in the next 100 years. I mean, I wouldn't mind so much if what you were advocating was not going to cost me and my children an arm and a leg to "avoid" - as if we could.

Even so, always good to read your comments. It helps to ground me in my understanding.